28 CRUCIFER^E. (mustard FAMILY.) 



5. A. Canadensis, L. Stem stout, simple, nearly smooth above ; leaves 

 thin, downy, lanceolate, slightly toothed, sessile by a narrow base, the lowest 

 coarsely or pinnatifid-toothed ; siliques curved, drooping, on rough pedicels ; 

 seeds winged. (A. falcata, Michx.) — Dry or rocky places in the upper districts. 

 May and June. — Stems 2° -3° high. Silique 2' -3' long. Flowers white. 

 Petals oblong-linear, not twice the length of the hairy calyx. 



6. A. laevigata, DC. Smooth and glaucous; stero erect; leaves linear 

 or lanceolate, entire or sparingly toothed, sagittate and clasping at the base ; 

 pedicels short; petals (whitish) narrow, slightly exserted ; silique elongated, 

 narrow-linear, recurved-spreading ; seed winged. — Rocky phiccs. North Caro- 

 lina, Tennessee, and northward. May. — Stem l°-20 high. Silique 2' -3' 

 long. 



7. SISYMBRIUM, L. Hedge-Mltstard. 



Silique linear or oblong, terete or somewhat angled, with 1 - 3-nen'ed valves. 

 Seeds in a single row in each cell, oblong, marginless. Cotyledons linear-oblong, 

 incumbent. — Herbs with simple or pinnately divided leaves. Flowers in ra- 

 cemes, small, white or yellow. 



1. S. canescens, Nutt. Pubescent and somewhat lioary ; stem simple or 

 sparingly branched; leaves bipinnatifid, with small mostly toothed lobes; ra- 

 cemes at length elongated ; silique shorter than the spreading pedicel. (Carda- 

 mine? multifida, DC.) — Waste ground, Florida, nortliward and westward. 

 March and April. (^ — Stem l°-2° high. Flowers small, greenish-white. 



2. S. Thaliana, Gaud. Stem slender, branching, hairy at the base ; leaves 

 hairv, toothed or entire, the lowest obovate or oblanccolatc, tufted, the others 

 small and scattered ; siliques linear, erect-spreading, twice as long as the pedi- 

 cels. — Rocks and sterile soil, Georgia and northward. Introduced. March 

 and April. @ — Stem 4' - 8' high. Flowers Avhite. 



3. S. oflleinale. Scop. Stem tall (2°-3°), branching, and with the nm- 

 cinate leaves pubescent; silique subulate, nearly sessile, appressed to the rachis. 

 — Waste grounds in the upper districts, and northward. Introduced. May - 

 Sept. (X — Flowers pale yellow. 



8. WARE A, Nutt. 



Silique linear, flattened, long-stalked, recur\-ed ; the valves 1-ncn-ed. Seeds 

 in a single row in each cell. Cotyledons oblong, flat, incumbent. — Smooth 

 and erect branching annuals. Leaves entire. Flowers showy, in corymb-like 

 racemes. Petals long-clawed, white or purple. 



1. W. amplexifolia, Nutt. Leaves oval and slightly clasping; petals 

 oval, bright-purple ; silique linear. — Sand hills, Florida. September. — Stem 

 lo-2° high. 



2. W. cuneifolia, Nutt. Leaves wedge-lanceolate ; petals obovate, white 

 or rarely pui-ple ; silique narrow-linear. — Sand hills, Florida and Georgia, 

 September. — Stem 1° - 2° high. 



